A coupling device for a small scale railway vehicle includes two shanks, a coil spring, and a spring prop. Each shank has coupling and lever ends, and is mounted on a pivot post for selectively pivoting, in opposite directions, between open and closed configurations. When open, the coupling ends are splayed apart for selective coupling to a second coupler. Any load borne by the coupling ends, from the second coupler, is transferred via the pivot post to the railway vehicle. The coil spring extends between the lever ends. It is biased towards the closed configuration. The spring prop partially bisects the coil spring and, via the coil spring, urges the shanks towards the closed configuration and the coupling ends, in opposing transverse directions, towards a centered position for secure coupling engagement with the second coupler.

Provided is a train set structure including a locomotive and a plurality of cars and track segments. The track segments can be connected and separated. The locomotive includes a driving unit, sprayer, liquid input hole, switch, and luminous body. The driving unit has driving rollers abutting against the track segments to drive the locomotive. The sprayer contains a liquid, with a vibrator disposed at the bottom of the sprayer, adapted to vibrate the liquid to produce aerosols, and electrically connected to a control circuit and a battery module for supply power to the vibrator. The switch is electrically connected to a music generator. The cars are connected and separated by connection hooks engaged with and disengaged from connection hole components respectively. The locomotive and cars move on the track segments automatically, accompanied by aerosols emitted from the sprayer, musical sounds, and flashes to achieve liveliness and entertainment.

Provided is a train set structure including a locomotive and a plurality of cars and track segments. The track segments can be connected and separated. The locomotive includes a driving unit, sprayer, liquid input hole, switch, and luminous body. The driving unit has driving rollers abutting against the track segments to drive the locomotive. The sprayer contains a liquid, with a vibrator disposed at the bottom of the sprayer, adapted to vibrate the liquid to produce aerosols, and electrically connected to a control circuit and a battery module for supply power to the vibrator. The switch is electrically connected to a music generator. The cars are connected and separated by connection hooks engaged with and disengaged from connection hole components respectively. The locomotive and cars move on the track segments automatically, accompanied by aerosols emitted from the sprayer, musical sounds, and flashes to achieve liveliness and entertainment.